Seeding implements, such as the John Deere model 665 Air Seeder utilize earth working tools mounted on chisel plow shanks for working the soil and depositing seeds behind the shanks. In certain soil conditions it is necessary to pack the soil firmly over the seeds to assure good, uniform germination. Various types of press wheels arrangements, such as trailing press wheel gangs or individual frame-mounted press wheel assemblies have been utilized, but these types of arrangements are often not suited for uneven terrain and do not track well during turns. Individual press wheel assemblies often are cumbersome and expensive, and space limitations on the main frame can hinder proper placement. Shank-mounted press wheels assemblies, such as shown in U.S. Pat. No. 4,579,071, are available for mounting on the shank of an implement such as an air seeder. Although such devices have improved press wheel tracking and are less bulky and easier to mount than some of the previously available press assemblies, vertical adjustment of such devices along the shank as well as adjustment of the press wheel arm with respect to the press wheel mounting bracket can be inconvenient and time consuming. Typically, press wheel arm down-pressure is achieved utilizing extension or torsion springs which are subject to fatigue and breakage adjacent the connecting or hooked end portions. Soil and trash flow around the shank adjacent the area of the press wheel assembly mounting can be impeded since portions of the press wheel bracket extend outwardly beyond the sides of the shank.